miRNA‑770‑5p expression is upregulated in patients with type 2 diabetes and miRNA‑770‑5p knockdown protects pancreatic β‑cell function via targeting BAG5 expression

MicroRNA (miR)-75p expression is increased in patients with type 2 diabetes mellitus (T2DM) compared with healthy controls; however, the roles and molecular mechanism underlying miR-75p in T2DM are not completely understood. In the present study, the reverse transcription-quantitative PCR (RT-qPCR) results indicated that miR-75p expression was significantly increased and Bcl-2 associated athanogene 5 (BAG5) expression was significantly decreased in the serum of patients with T2DM compared with healthy volunteers. TargetScan and a dual luciferase reporter gene system were used to predict and verify BAG5 as a target gene of miR-75p. Additionally, the RT-qPCR results demonstrated that miR-75p expression was significantly increased and BAG5 expression was significantly decreased in uric acid (UA)-treated Min6 cells compared with control cells. Min6 cells were transfected with miR-75p inhibitor and BAG5-small interfering (si)RNA to alter expression levels. The results indicated that miR-75p negatively regulated BAG5. The effect of miR-75p knockdown on UA-induced pancreatic β-cell damage and dysfunction was subsequently assessed. Min6 cells were transfected with miR-75p inhibitor or miR-75p inhibitor + BAG5-siRNA for 48 h, followed by treatment with or without 5 mg/dl UA for 24 h. Cell viability, apoptosis, apoptosis-related factor expression levels and insulin secretion were assessed. The results demonstrated that UA treatment significantly reduced cell viability, increased cell apoptosis and reduced insulin secretion in Min6 cells compared with the control group. miR-75p inhibitor significantly attenuated UA-induced injury and dysfunction of Min6 cells, whereas BAG5 knockdown abolished the protective effects of miR-75p inhibitor on UA-damaged Min6 cells. In conclusion, miR-75p was highly expressed in the serum of patients with T2DM compared with healthy volunteers. In UA-treated pancreatic β-cells, compared with the inhibitor control group, miR-75p knockdown regulated the expression of apoptosis-related genes, increased cell viability, inhibited cell apoptosis and increased insulin secretion by targeting BAG5. Therefore, the present study suggested that miR-75p inhibitor may serve a protective role in T2DM.

文章引用产品列表